Heating pumps typically include a pump housing having a chamber, a heater fixed to the pump housing and received in the chamber, an impeller received in the pump housing, and a motor fixed to the pump housing for driving the impeller. The entire pump housing of one typical heating pump is made of plastic, which includes a top plate facing the motor and an inlet tube extending from an exterior of the top plate to an interior of the chamber. The heater includes two connecting heads and a spiral main body having multiple rings. The two connecting heads extend through and are locked to the top plate. The main body surrounds part of the inlet tube located in the chamber. During operation, the water enters the impeller via the inlet tube. The water is then expelled from the pump chamber via an outlet by the impeller. The water is heated as it flows through the main body of the heater on its way to the outlet. In this design, the main body of the heater is in the form of multiple rings, which obstructs the flow of the water and hence leads to low pump efficiency.